Principles of ventilation

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Ventilation is the planned removal heat, smoke and fire gases from a burning structure - this in effect supplies cool fresh air. Ventilation in a large fire should happen as or before the interior rescue crews enter the building.

The benefits of ventilation include:

  • Improved visibility - helps with the finding and rescue of victims,
  • Less chance of disorientation inside the smoke filled building.
  • Reduced temperatures at the scene
  • Reduced possibility of backdraft or flashover (reduces the spread of fire)
  • Safer conditions
  • Better chance of victim survival:
  • More easily located,
  • Lower temperatures,
  • Lower risk of smoke inhalation.

Ventilating the fire

Ventilation should take place at the highest point near the burning side of the building. In a single story house, open or remove the windows in the room where the fire is burning. Ventilation may be :

  • vertical - opening through the roof,
  • Horizontal - opening of door and windows.


Fires and firefighting is dangerous and we need to be aware of the risks.

  • Always wear the correct personal protective equipment (PPE) and SCBA.
  • Be aware of the possibility of smoke and flashback so work with the wind at your back or side when cutting vent holes or venting windows
  • Vertical ventilation: Check roof stability and only have the minimum personnel on the roof. Always work from a roof ladder on a pitched roof. and have a secondary escape route from the roof. Remove crew from roof after ventilation hole is completed.
  • Be ready to fight the fire - the ventilation supplies fresh oxygen to the fire and can lead to fire spread.